# Find element with the maximum set bits in an array

Given an array arr[]. The task is to find an element from arr[] which has the maximum count of set bits.

Examples:

Input: arr[] = {10, 100, 1000, 10000}
Output: 1000
Binary(10) = 1010 (2 set bits)
Binary(100) = 1100100 (3 set bits)
Binary(1000) = 1111101000 (6 set bits)
Binary(10000) = 10011100010000 (5 set bits)

Input: arr[] = {3, 2, 4, 7, 1, 10, 5, 8, 9, 6}
Output: 7

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach: Traverse the array and find the count of set bits in the current element and find the element with the maximum number of set bits.

Below is the implementation of the above approach:

## C++

 `// C++ implementation of the approach  ` ` `  `#include ` `using` `namespace` `std; ; ` ` `  `// Function to return the element from the array  ` `// which has the maximum set bits  ` `int` `maxBitElement(``int` `arr[], ``int` `n)  ` `{  ` ` `  `    ``// To store the required element and  ` `    ``// the maximum set bits so far  ` `    ``int` `num = 0, max = -1;  ` ` `  `    ``for` `(``int` `i = 0; i < n; i++) {  ` ` `  `        ``// Count of set bits in  ` `        ``// the current element  ` `        ``int` `cnt = __builtin_popcount(arr[i]);  ` ` `  `        ``// Update the max  ` `        ``if` `(cnt > max) {  ` `            ``max = cnt;  ` `            ``num = arr[i];  ` `        ``}  ` `    ``}  ` `    ``return` `num;  ` `}  ` ` `  `// Driver code  ` `int` `main()  ` `{  ` `    ``int` `arr[] = { 3, 2, 4, 7, 1, 10, 5, 8, 9, 6 };  ` `    ``int` `n = ``sizeof``(arr)/ ``sizeof``(arr) ;  ` `     `  `    ``cout << maxBitElement(arr, n) << endl;  ` `     `  `return` `0 ; ` ` `  `// This code is contributed by AnkitRai01  ` `}  `

## Java

 `// Java implementation of the approach ` `class` `GFG { ` ` `  `    ``// Function to return the element from the array ` `    ``// which has the maximum set bits ` `    ``static` `int` `maxBitElement(``int` `arr[], ``int` `n) ` `    ``{ ` ` `  `        ``// To store the required element and ` `        ``// the maximum set bits so far ` `        ``int` `num = ``0``, max = -``1``; ` ` `  `        ``for` `(``int` `i = ``0``; i < n; i++) { ` ` `  `            ``// Count of set bits in ` `            ``// the current element ` `            ``int` `cnt = Integer.bitCount(arr[i]); ` ` `  `            ``// Update the max ` `            ``if` `(cnt > max) { ` `                ``max = cnt; ` `                ``num = arr[i]; ` `            ``} ` `        ``} ` `        ``return` `num; ` `    ``} ` ` `  `    ``// Driver code ` `    ``public` `static` `void` `main(String[] args) ` `    ``{ ` `        ``int` `arr[] = { ``3``, ``2``, ``4``, ``7``, ``1``, ``10``, ``5``, ``8``, ``9``, ``6` `}; ` `        ``int` `n = arr.length; ` `        ``System.out.print(maxBitElement(arr, n)); ` `    ``} ` `} `

## Python3

 `# Python 3 implementation of the approach  ` ` `  `# Function to return the element from the array  ` `# which has the maximum set bits  ` `def` `maxBitElement(arr, n): ` `     `  `    ``# To store the required element and  ` `    ``# the maximum set bits so far  ` `    ``num ``=` `0` `    ``max` `=` `-``1` ` `  `    ``for` `i ``in` `range``(n): ` `         `  `        ``# Count of set bits in  ` `        ``# the current element  ` `        ``cnt ``=` `bin``(arr[i]).count(``'1'``) ` ` `  `        ``# Update the max  ` `        ``if` `(cnt > ``max``): ` `            ``max` `=` `cnt ` `            ``num ``=` `arr[i] ` `    ``return` `num ` ` `  `# Driver code  ` `if` `__name__ ``=``=` `'__main__'``: ` `    ``arr ``=` `[``3``, ``2``, ``4``, ``7``, ``1``,  ` `          ``10``, ``5``, ``8``, ``9``, ``6``]  ` `    ``n ``=` `len``(arr) ` `     `  `    ``print``(maxBitElement(arr, n)) ` `     `  `# This code is contributed by ` `# Surendra_Gangwar `

## C#

 `// C# implementation of the approach ` `using` `System; ` ` `  `class` `GFG ` `{ ` ` `  `    ``// Function to return the element from the array ` `    ``// which has the maximum set bits ` `    ``static` `int` `maxBitElement(``int` `[]arr, ``int` `n) ` `    ``{ ` ` `  `        ``// To store the required element and ` `        ``// the maximum set bits so far ` `        ``int` `num = 0, max = -1; ` ` `  `        ``for` `(``int` `i = 0; i < n; i++) ` `        ``{ ` ` `  `            ``// Count of set bits in ` `            ``// the current element ` `            ``int` `cnt = BitCount(arr[i]); ` ` `  `            ``// Update the max ` `            ``if` `(cnt > max) ` `            ``{ ` `                ``max = cnt; ` `                ``num = arr[i]; ` `            ``} ` `        ``} ` `        ``return` `num; ` `    ``} ` `    ``static` `int` `BitCount(``int` `n) ` `    ``{ ` `        ``int` `count = 0; ` `        ``while` `(n != 0) ` `        ``{ ` `            ``count++; ` `            ``n &= (n - 1); ` `        ``} ` `        ``return` `count; ` `    ``}  ` `     `  `    ``// Driver code ` `    ``public` `static` `void` `Main(String[] args) ` `    ``{ ` `        ``int` `[]arr = { 3, 2, 4, 7, 1, 10, 5, 8, 9, 6 }; ` `        ``int` `n = arr.Length; ` `        ``Console.Write(maxBitElement(arr, n)); ` `    ``} ` `} ` ` `  `// This code contributed by Rajput-Ji `

## PHP

 ` ``\$max``) ` `        ``{ ` `            ``\$max` `= ``\$cnt``; ` `            ``\$num` `= ``\$arr``[``\$i``]; ` `        ``} ` `    ``} ` `    ``return` `\$num``; ` `} ` ` `  `function` `BitCount(``\$n``) ` `{ ` `    ``\$count` `= 0; ` `    ``while` `(``\$n` `!= 0) ` `    ``{ ` `        ``\$count``++; ` `        ``\$n` `&= (``\$n` `- 1); ` `    ``} ` `    ``return` `\$count``; ` `}  ` `     `  `// Driver code ` `\$arr` `= ``array``(3, 2, 4, 7, 1, 10, 5, 8, 9, 6 ); ` `\$n` `= ``count``(``\$arr``); ` `echo``(maxBitElement(``\$arr``, ``\$n``)); ` ` `  `// This code contributed by PrinciRaj1992 ` `?> `

Output:

```7
```

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